Presence is a concept promoted in various Internet Engineering Task Force (IETF) documents as the subscription to and notification of changes in a communications state of a user. The state may for instance consist of the set of communications means, communications address, and status of that user. A presence protocol provides such a service over an IP network. An extension to the Session Initiation Protocol (SIP) has been proposed by J. Rosenberg et al. for control of presence in the IMPP WG entitled “SIP Extensions for Presence” and which can be found at draft-rosenberg-impp-presence-00.txt, Jun. 15, 2000. The SIP is from the SIP WG and is described at RFC 2543 by Handley et al., entitled “SIP: Session Initiation Protocol” Aug. 6, 2000 found at draft-ietf-sip-rfc2543bis-0.1.ps. It is an application layer control (signaling) protocol for creating, modifying and terminating sessions with one or more participants.
Instant messaging is widely used today but mostly using a proprietary system to exchange content between a set of participants in real time. Unfortunately, the user of such a proprietary system is tightly bound to the provider and cannot use the service for purposes other than offered by the provider, much less inter-operate with other instant messaging services. In effect, the presence of the user is tightly bound to the proprietary system, and the user cannot get out of this straight jacket. This is a problem. SIP extensions have also been proposed for instant messaging (“SIP extension for Instant Messaging”) at draft-rosenberg-impp-im-00.txt, Jun. 15, 2000, also by J. Rosenberg et al. of the IMPP WG of the IETF. In that document, motivations are provided on why SIP is an ideal platform for instant messaging (IM), why IM should be completely separated from presence, and how to perform IM with SIP. SIP extensions for message waiting indication have likewise been proposed in the IETF draft-mahy-sip-message-waiting-00.txt, July 2000.
At the IETF it is therefore proposed to use the SIP for registering the user and to use the same mechanism to notify the user about message waiting.
A “Basic SloP Architecture Proposal” by J. Loughney et al, Jul. 15, 2000, IETF draft-loughney-spatial-arch-00.txt proposes a simple architecture supporting the transport of spatial location information to allow services based on spatial location information to inter-operate. The exchange of location information is attractive for exchange of information between devices in both wired and wireless networks.
A problem is therefore how to implement presence and messaging for wired and wireless IP Networks.